Azo dyestuffs containing chromium and process of making



STATES UNETE PATENr- QFFIC HANS KAMMEBER, F MANNI-IEIM, GERMANY, ASSIGNOR TO GENERAL ANILINE WORKS, IN (3., OF NEW YORK, N. Y., A CORPORATION OF DELAWARE AZO .IDYESTUFFS CONTAINING CHROMIUM AND PROCESS OF MAKING No Drawing. Application filed October 13, 1927, Serial No. 226,042, and in Germany October 22, 1926.

I have found thatazo dyestuffs with excellent properties are obtained by combining the Vdiazo compounds of o-aminonaphthol, or its diazotisable derivatives, with 1 5 naphthol-8-sulphonic acid. By treating the resulting azo dyestufl's, either in substance or on the fibre with chromium compounds, they can be converted into valuable chromiferous dyestuffs, which are distinguished by clarity 10 of shade and excellent fa-stness to washing and milling. The following examples further illustrate the nature of this invention which however is not restricted to these examples.

Example 1 1-amino-2-naphtholAc-sulphonic acid is diazotized, coupled with 1-naphthol-8-sul phonic acid in astrong solution of caustic 2 alkali, and further treated in any suitable or.

known manner. The resultin d estufl' which probably has the followingformulai OH SIOaH Example 2 parts of the dyestutt prepared in a strong solution of caustic alkali from l-naphthol-8-sulphonic acid and the nitrated diazo compound of lsamino-2-naphthol-4L-sulphonic acid which dyestuff probably has the formula: 7

( m sour on NO;

I son; are heated to 120 centigrade in an autoclave for 3 hours with 200 partsof a solution of chromiumformate containing 10.5 parts of Cr O the solution being then evaporated.

The chromiferous dyestufi, containing about one atom of chromium for each molecule of the above described azo compound, gives very fast black dyeings on wool.

What I claim is:

1. The process of producing new azo dyestuffs containing chromium, which consists in coupling the diazo compound of a l-amino- Q-naphthol with 1-naphthol-8-sulfonic acid and treating the product thus obtained with a chromium compound.

2. The process of producing new azo dyestufis containing chromium, which consists in coupling the diazo compound of a l-amino- Q-naphthol with 1-naphthol-8-sulfonic acid and boiling the product thus obtained-with chromium formats solution.

3. The process of producing a new azo dyestuff containing chromium, which consists in coupling the diazo compound of 1-amino- Q-naphtholl-sulfonic acid with l-naphthol- 8-sulfonic acid and boiling the product thus obtained with chromium formate solution.

4. As new articles of manufacture, the new azo dyestuifs containing chromium obtainable by coupling the diazo compound of a 1-amino-2-naphthol with l-naphthol-S-sul- 'fonic acid and treating the product thus obtained with a chromium compound.

5. As a new article of manufacture, the new 2120 dyestufl containing chromium, which gives clear blue dyeings with a greenish tinge on wool, obtainable by coupling the diazo compound of l-amino-2-naphthol-4-sulfonic acid with l-naphthol-S-sulfonic acid and boiling the product thus obtained with chromium formate solution.

In testimony whereof I have hereunto set my hand.

HANS KAMMERER. 

